Timber decks or fences comprising two or more timber joists spanned by a plurality of parallel planks nailed to the joists are typically constructed by driving nails down through the exposed face surface of the planks into the joists. This method is undesirable for several reasons. With hammering, it is easy to miss and hit the plank thus denting or marking it.
Flat head nails hold well but can be seen and detract from the aesthetic appearance of the deck and the nail head will often discolour the area around it.
Bullet head nails are not as displeasing in appearance but as the head is usually countersunk, water can be retained in the nail hole which leads to rot and rust.
Nails of all types can work up such that the nail head is above the plank surface and cause a safety hazard.
A particular problem associated with timber decking is that water can get into the joint between the plank and joist and causes rot.
One alternative which produces a more aesthetic surface is to countersink a wood screw and to plug the hole above the screw with a plug of wood. This method is expensive and time consuming; the plugs work out in time and the screw holes fill with water.
Therefore, it is desirable to have a fastening device which overcomes the shortcomings of the prior art timber fastenings and which attaches planks to a deck with an unmarked upper surface, especially if it spaces the planks from the joist.
It is further desirable that the fastening device provides a means for spacing the planks from one another.
U.S. Pat. No. 4,965,980 (Leavens) discloses an anchoring bracket for use in attaching substantially parallel planks to a generally transverse member or joist and in spacing the planks and generally comprises a spacer side and a joist attachment side.
The spacer side has a spacing portion for placement on the top of the joist for spacing a board from the joist and an extended portion attached to the spacing portion for extending over the edge of the joist. A plank spacer tab, affixed to the spacer side, projects generally perpendicularly upward therefrom for positioning directly adjacent a plank for controlling the spacing thereof.
The joist attachment side includes an attachment portion disposed generally perpendicular to the spacer side for attachment to the side of the joist and an angled portion connecting the attachment portion to the outer end of the extended portion. The angled portion includes holes for receiving a fastener for fastening a plank to the bracket.
An alternate embodiment includes a plurality of plank spacer tabs affixed at intervals to the spacer side; each for positioning directly adjacent a plank for controlling the spacing of a plurality of planks.
While the deck bracket of Leaven has certain advantages over the prior art, it also has a number of disadvantages. Of these, the major disadvantage is that it requires the operator to have access to a region below the deck to enable the fasteners to be inserted upwardly through the holes in the angled portion and then driven into the deck planks. Moreover, the plank spacer tabs are at fixed modular distances and cannot easily accommodate variations in the width of the deck planks.
U.S. Pat. No. 4,925,141 (Classen) describes a deck clip having a pair of spaced joist attachment plates to attach the clip on either side of a joist. Bridging the spaced attachment plates is an upright planar member having oppositely directed pointed tangs spaced on either side of the upright planar member. The planar member optionally has projections which act as spacers between adjacent planks.
While generally effective for its purpose, this clip does not include spacing flanges to elevate the planks above the surface of the joist to resist rot. More importantly however, the non aligned axes of the plank penetrating tangs makes these clips difficult to fix without skewing.
Other embodiments of the Classen clip have misaligned plank penetrating tangs and do not possess spacing flanges to separate the planks from the joists.
U.S. Pat. No. 5,027,573 describes a connector bracket for use in construction of timber planked decks and the like.
This bracket is attachable to an edge of a plank and includes a projecting lip which engages under the edge of an adjacent plank which has been skew nailed through its edge to a joist to provide a hidden fastening means.
The major disadvantage of this type of fastening is that it is indirectly connected to an adjacent plank. Planks which are skew nailed at their edges are prone to splitting and this releases the indirect connection with the adjacent plank allowing substantial relative movement between the planks.
U.S. Pat. No. 4,844,651 (Partridge) describes a decking clip which attaches to the edge of a decking plank and also on the undersurface thereof leaving an apertured lip projecting adjacent the lower surface of the plank.
These clips must be pre-attached to a deck plank on both edges thereof with clips along one edge aligned with spaced joists and clips along the opposite edge misaligned with the joists.
Planks are secured to the joists by engaging the misaligned lips under a plank fixed to the joists and securing the opposite side of the plank to the joists with fasteners extending through the apertured lips.
Although effective for their purpose, these clips do not include integral plank spacers, are expensive in that two rows of clips are required and otherwise are time consuming to attach.